What is Maltodextrin?
Maltodextrin is a white, flavorless powder derived from starches such as corn, rice, potatoes, or wheat. It is produced through a process called partial hydrolysis, where acids or enzymes break down the starch into smaller glucose polymer chains. Though it comes from natural sources, it is considered a highly processed food additive. In the food industry, maltodextrin serves many functions, including as a bulking agent, a thickener, a fat replacer, and a carrier for flavors.
The Natural Carbohydrate in Milk: Lactose
The primary carbohydrate found naturally in all mammal milk is lactose. Lactose is a disaccharide, or a sugar made of two smaller sugar units—glucose and galactose. In cow's milk, lactose makes up approximately 4.9% of the composition. It is the most abundant solid component and is the main source of energy for infants drinking natural milk. Unlike maltodextrin, lactose is not added to fresh milk; it is a fundamental part of its natural makeup.
Maltodextrin vs. Lactose: A Comparison
To understand the difference, a comparison of the key characteristics of these two carbohydrates is useful.
| Characteristic | Maltodextrin | Lactose |
|---|---|---|
| Origin | Derived from plant starches (e.g., corn, rice) through processing. | Naturally occurring in mammal milk. |
| Sweetness | Has a neutral to slightly sweet taste. | Moderately sweet. |
| Digestion Speed | Rapidly digested and absorbed by the body. | Digested and absorbed more slowly than maltodextrin. |
| Processing | A highly processed food additive. | A natural component of milk, not an additive. |
| Use in Dairy | Added to processed dairy products for texture, bulk, or energy. | Naturally present in all fresh milk. |
Why is Maltodextrin Added to Some Dairy Products?
While maltodextrin is not in fresh, liquid milk, it is a key ingredient in many processed dairy-based foods for functional reasons:
- Infant Formula: It is a common carbohydrate source in some infant formulas. Manufacturers may use it to increase the energy content or to reduce the overall sweetness compared to using only lactose. It also helps create a smooth consistency and improves the solubility of the powder when mixed with water.
- Low-Fat and Fat-Free Dairy: In products like reduced-fat yogurt, ice cream, and creamy desserts, maltodextrin can be used as a fat replacer. It mimics the creamy mouthfeel and texture that would otherwise be lost when the fat is removed, adding body and viscosity without contributing fat calories.
- Fermented Dairy Cultures: In trace amounts, maltodextrin is used in freeze-dried cultures for fermented dairy products like yogurt and cheese. It acts as a food source to help jumpstart the cultures when they are added to the milk. The amount used is very small and is typically consumed by the cultures during fermentation.
- Milk Powder: In dried or powdered dairy products, maltodextrin is added to improve their solubility, prevent clumping, and enhance shelf life.
Maltodextrin as a Milk Adulterant
In some regions, particularly in certain developing countries, maltodextrin has been identified as an illegal adulterant in liquid milk. It may be added to increase the volume of the milk and boost the 'solids not fat' (SNF) content, which can be measured during quality control tests. This practice is dangerous, as adulterated milk can have serious health consequences. The presence of maltodextrin in liquid milk is not an intended or regulated use, but rather an illicit one that food safety authorities must monitor. Test strips exist for the detection of maltodextrin in milk, highlighting that it is an unnatural contaminant.
How to Identify Maltodextrin in Dairy Products
Because maltodextrin is so commonly used as a food additive, it is important to check the ingredient list on any processed dairy products you buy. While fresh, refrigerated milk will not list it, many other items will. Food labeling regulations typically require that ingredients be listed in order of predominance by weight. If maltodextrin makes up more than 1% of the final product, it must be declared on the label. However, trace amounts used in cultures for fermentation may not be required to be listed. Look out for it in items like flavored yogurts, low-fat sour cream, and some ice creams.
Conclusion
In summary, there is no maltodextrin in milk that has come directly from a mammal and has been processed for drinking. The natural carbohydrate in milk is lactose. Maltodextrin is a processed, starch-derived ingredient that is intentionally added to a variety of other dairy products, including infant formulas, low-fat items, and powdered mixes, for its texturizing, bulking, and stabilizing properties. In liquid milk, its presence would indicate illegal adulteration. As a consumer, the best way to monitor your intake of maltodextrin is by carefully reading the ingredient lists on all processed dairy foods and beverages.
